170 research outputs found

    Hematocrit and the Risk of Recurrent Venous Thrombosis: A Prospective Cohort Study

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    BACKGROUND: Venous thromboembolism (VTE) is a multicausal disease which recurs. Hematocrit is associated with a thrombotic risk. We aimed to investigate if hematocrit is associated with the recurrence risk. METHODS: Patients with a first VTE were followed after anticoagulation. Patients with VTE provoked by a transient risk factor, natural inhibitor deficiency, lupus anticoagulant, homozygous or double heterozygous defects, cancer, or long-term antithrombotic treatment were excluded. The study endpoint was recurrent VTE. RESULTS: 150 (23%) of 653 patients had recurrence. Only high hematocrit was significantly associated with recurrence risk [hazard ratio (HR) for 1% hematocrit increase with the third tertile 1.08; 95% CI 1.01-1.15]. No or only a weak association for hematocrits within the first and second tertile was seen (HR 1.03; 95% CI 0.97-1.09, and 1.07; 95% CI 1.00-1.13). Hematocrit was associated with recurrence risk only among women. After five years, the probability of recurrence was 9.9% (95% CI 3.7%-15.7%), 15.6% (95% CI 9.7%-21.2%) and 25.5% (95% CI 15.1%-34.6%) in women, and was 29.2% (95% CI 21.1%-36.5%), 30.1% (95% CI 24.1%-35.7%) and 30.8% (95% CI 22.0%-38.7%) in men for hematocrits in the first, second and third tertile, respectively. Men had a higher recurrence risk (1.9; 95% CI 1.1-2.7; p = 0.03), which dropped by 23.5% after adjustment for hematocrit. Hematocrit was not a significant mediator of the sex-difference in recurrence risk (p = 0.223). CONCLUSIONS: High hematocrit is associated with the recurrence only in women. The different recurrence risk between men and women is possibly partly explained by hematocrit

    Characterization of Polymorphic Microsatellites in the Giant Bulldog Ant, Myrmecia brevinoda and the Jumper Ant, M. pilosula

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    The ant genus Myrmecia Fabricius (Hymenoptera: Formicidae) is endemic to Australia and New Caledonia, and has retained many biological traits that are considered to be basal in the family Formicidae. Here, a set of 16 dinucleotide microsatellite loci were studied that are polymorphic in at least one of the two species of the genus: the giant bulldog ant, M. brevinoda Forel, and the jumper ant, M. pilosula Smith; 13 are novel loci and 3 are loci previously published for the genus Nothomyrmecia Clark (Hymenoptera: Formicidae). In M. brevinoda, the total of 12 polymorphic microsatellites yielded a total of 125 alleles, ranging from 3 to 18 with an average of 10.42 per locus; the observed and expected heterozygosities ranged from 0.4000 to 0.9000 and from 0.5413 to 0.9200, respectively. In M. pilosula, the 9 polymorphic loci yielded a total of 67 alleles, ranging from 3 to 12 with an average of 7.44 per locus; the observed and expected heterozygosities ranged from 0.5625 to 0.9375 and from 0.4863 to 0.8711, respectively. Five loci were polymorphic in both target species. In addition, 15 out of the 16 loci were successfully amplified in M. pyriformis. These informative microsatellite loci provide a powerful tool for investigating the population and colony genetic structure of M. brevinoda and M. pilosula, and may also be applicable to a range of congeners considering the relatively distant phylogenetic relatedness between M. pilosula and the other two species within the genus Myrmecia

    Progression and mortality in patients with CKD attending outpatient nephrology clinics across Europe: A novel analytic approach

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    The incidence of renal replacement therapy (RRT) varies across countries. Yet, little is known about the epidemiology of chronic kidney disease (CKD) outcomes. Our aim was to describe progression and mortality risk in CKD patients not on RRT attending outpatient nephrology clinics across Europe. We used individual data from nine CKD cohorts participating in the European CKD Burden Consortium. A joint model was used to estimate mean eGFR change and mortality risk simultaneously, thereby accounting for mortality risk when estimating eGFR decline and vice versa, while also correcting for the measurement error in eGFR. Results were adjusted for important risk factors (baseline eGFR, age, sex, albuminuria, primary renal disease, diabetes, hypertension, obesity and smoking). 27,771 patients from five countries were included. The adjusted mean annual eGFR decline varied from 0.77 (95%CI 0.45,1.08) ml/min/1.73m2 in the Belgium cohort to 2.43 (95%CI 2.11,2.75) ml/min/1.73m2 in the Spanish cohort. As compared to the Italian PIRP cohort, the adjusted mortality hazard ratio varied from 0.22 (95%CI 0.11,0.43) in the London LACKABO cohort to 1.30 (95%CI 1.13,1.49) in the English CRISIS cohort. Outcomes in CKD patients attending outpatient nephrology clinics varied markedly across European regions. Although eGFR decline showed minor variation, the most variation was observed in CKD mortality. Our results suggest that different healthcare organization systems are potentially associated with differences in outcome of CKD patients within Europe. These results can be used by policy makers to plan resources on a regional, national and European level

    The Cow: Discovery of a Luminous, Hot, and Rapidly Evolving Transient

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    We present the ATLAS discovery and initial analysis of the first 18 days of the unusual transient event, ATLAS18qqn/AT2018cow. It is characterized by a high peak luminosity (~1.7 × 1044 erg s−1), rapidly evolving light curves (>5 mag rise to peak in ~3.5 days), and hot blackbody spectra, peaking at ~27,000 K that are relatively featureless and unchanging over the first two weeks. The bolometric light curve cannot be powered by radioactive decay under realistic assumptions. The detection of high-energy emission may suggest a central engine as the powering source. Using a magnetar model, we estimated an ejected mass of 0.1–0.4 M ⊙{}_{\odot }, which lies between that of low-energy core-collapse events and the kilonova, AT2017gfo. The spectra cooled rapidly from 27,000 to 15,000 K in just over two weeks but remained smooth and featureless. Broad and shallow emission lines appear after about 20 days, and we tentatively identify them as He i although they would be redshifted from their rest wavelengths. We rule out that there are any features in the spectra due to intermediate mass elements up to and including the Fe group. The presence of r-process elements cannot be ruled out. If these lines are due to He, then we suggest a low-mass star with residual He as a potential progenitor. Alternatively, models of magnetars formed in neutron star mergers, or accretion onto a central compact object, give plausible matches to the data

    SN 2017dio: A Type-Ic Supernova Exploding in a Hydrogen-rich Circumstellar Medium

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    SN 2017dio shows both spectral characteristics of a type-Ic supernova (SN) and signs of a hydrogen-rich circumstellar medium (CSM). Prominent, narrow emission lines of H and He are superposed on the continuum. Subsequent evolution revealed that the SN ejecta are interacting with the CSM. The initial SN Ic identification was confirmed by removing the CSM interaction component from the spectrum and comparing with known SNe Ic and, reversely, adding a CSM interaction component to the spectra of known SNe Ic and comparing them to SN 2017dio. Excellent agreement was obtained with both procedures, reinforcing the SN Ic classification. The light curve constrains the pre-interaction SN Ic peak absolute magnitude to be around Mg=−17.6{M}_{g}=-17.6 mag. No evidence of significant extinction is found, ruling out a brighter luminosity required by an SN Ia classification. These pieces of evidence support the view that SN 2017dio is an SN Ic, and therefore the first firm case of an SN Ic with signatures of hydrogen-rich CSM in the early spectrum. The CSM is unlikely to have been shaped by steady-state stellar winds. The mass loss of the progenitor star must have been intense, M˙∌0.02(Ï”Hα/0.01)−1\dot{M}\sim 0.02{({\epsilon }_{{\rm{H}}\alpha }/0.01)}^{-1} (vwind/500{v}_{\mathrm{wind}}/500 km s−1) (vshock/({v}_{\mathrm{shock}}/10,000 km s−1)−3 M ⊙ yr−1, peaking at a few decades before the SN. Such a high mass-loss rate might have been experienced by the progenitor through eruptions or binary stripping

    Widespread sensorimotor and frontal cortical atrophy in Amyotrophic Lateral Sclerosis

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    BACKGROUND: Widespread cortical atrophy in Amyotrophic Lateral Sclerosis (ALS) has been described in neuropathological studies. The presence of cortical atrophy in conventional and scientific neuroimaging has been a matter of debate. In studies using computertomography, positron emission tomography, proton magnetic resonance spectroscopy and conventional T2-weighted and proton-weighted images, results have been variable. Recent morphometric studies by magnetic resonance imaging have produced conflicting results regarding the extent of grey and white matter involvement in ALS patients. METHODS: The authors used optimized voxel-based morphometry as an unbiased whole brain approach to detect differences between regional grey and white matter volumes. Seventeen patients with a diagnosis of ALS according to El-Escorial criteria and seventeen age-matched controls received a high resolution anatomical T1 scan. RESULTS: In ALS patients regional grey matter volume (GMV) reductions were found in the pre- and postcentral gyrus bilaterally which extended to premotor, parietal and frontal regions bilaterally compared with controls (p < 0.05, corrected for the entire volume). The revised ALS functional rating scale showed a positive correlation with GMV reduction of the right medial frontal gyrus corresponding to the dorsolateral prefrontal cortex. No significant differences were found for white matter volumes or when grey and white matter density images were investigated. There were no further correlations with clinical variables found. CONCLUSION: In ALS patients, primary sensorimotor cortex atrophy can be regarded as a prominent feature of the disease. Supporting the concept of ALS being a multisytem disorder, our study provides further evidence for extramotor involvement which is widespread. The lack of correlation with common clinical variables probably reflects the fact that heterogeneous disease processes underlie ALS. The discrepancy within all published morphometric studies in ALS so far may be related to differences in patient cohorts and several methodological factors of the data analysis process. Longitudinal studies are required to further clarify the time course and distribution of grey and white matter pathology during the course of ALS

    Interest groups in multiple streams:specifying their involvement in the framework

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    Although interests inhabit a central place in the multiple streams framework (MSF), interest groups have played only a minor role in theoretical and empirical studies until now. In Kingdon’s original conception, organized interests are a key variable in the politics stream. Revisiting Kingdon’s concept with a particular focus on interest groups and their activities—in different streams and at various levels—in the policy process, we take this argument further. In particular, we argue that specifying groups’ roles in other streams adds value to the explanatory power of the framework. To do this, we look at how interest groups affect problems, policies, and politics. The influence of interest groups within the streams is explained by linking the MSF with literature on interest intermediation. We show that depending on the number of conditions and their activity level, interest groups can be involved in all three streams. We illustrate this in case studies reviewing labor market policies in Germany and chemicals regulation at the European level

    Anthropogenic perturbation of the carbon fluxes from land to ocean

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    A substantial amount of the atmospheric carbon taken up on land through photosynthesis and chemical weathering is transported laterally along the aquatic continuum from upland terrestrial ecosystems to the ocean. So far, global carbon budget estimates have implicitly assumed that the transformation and lateral transport of carbon along this aquatic continuum has remained unchanged since pre-industrial times. A synthesis of published work reveals the magnitude of present-day lateral carbon fluxes from land to ocean, and the extent to which human activities have altered these fluxes. We show that anthropogenic perturbation may have increased the flux of carbon to inland waters by as much as 1.0 Pg C yr-1 since pre-industrial times, mainly owing to enhanced carbon export from soils. Most of this additional carbon input to upstream rivers is either emitted back to the atmosphere as carbon dioxide (~0.4 Pg C yr-1) or sequestered in sediments (~0.5 Pg C yr-1) along the continuum of freshwater bodies, estuaries and coastal waters, leaving only a perturbation carbon input of ~0.1 Pg C yr-1 to the open ocean. According to our analysis, terrestrial ecosystems store ~0.9 Pg C yr-1 at present, which is in agreement with results from forest inventories but significantly differs from the figure of 1.5 Pg C yr-1 previously estimated when ignoring changes in lateral carbon fluxes. We suggest that carbon fluxes along the land–ocean aquatic continuum need to be included in global carbon dioxide budgets.Peer reviewe

    DNA methylation levels in candidate genes associated with chronological age in mammals are not conserved in a long-lived seabird

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    © 2017 De Paoli-Iseppi et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Most seabirds do not have any outward identifiers of their chronological age, so estimation of seabird population age structure generally requires expensive, long-term banding studies. We investigated the potential to use a molecular age biomarker to estimate age in short-tailed shearwaters (Ardenna tenuirostris). We quantified DNA methylation in several A. tenuirostris genes that have shown age-related methylation changes in mammals. In birds ranging from chicks to 21 years of age, bisulphite treated blood and feather DNA was sequenced and methylation levels analysed in 67 CpG sites in 13 target gene regions. From blood samples, five of the top relationships with age were identified in KCNC3 loci (CpG66: R2 = 0.325, p = 0.019). In feather samples ELOVL2 (CpG42: R2 = 0.285, p = 0.00048) and EDARADD (CpG46: R2 = 0.168, p = 0.0067) were also weakly correlated with age. However, the majority of markers had no clear association with age (of 131 comparisons only 12 had a p-value &lt; 0.05) and statistical analysis using a penalised lasso approach did not produce an accurate ageing model. Our data indicate that some age-related signatures identified in orthologous mammalian genes are not conserved in the long-lived short tailed shearwater. Alternative molecular approaches will be required to identify a reliable biomarker of chronological age in these seabirds

    A kilonova as the electromagnetic counterpart to a gravitational-wave source

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    Gravitational waves were discovered with the detection of binary black-hole mergers1 and they should also be detectable from lower-mass neutron-star mergers. These are predicted to eject material rich in heavy radioactive isotopes that can power an electromagnetic signal. This signal is luminous at optical and infrared wavelengths and is called a kilonova2,3,4,5. The gravitational-wave source GW170817 arose from a binary neutron-star merger in the nearby Universe with a relatively well confined sky position and distance estimate6. Here we report observations and physical modelling of a rapidly fading electromagnetic transient in the galaxy NGC 4993, which is spatially coincident with GW170817 and with a weak, short Îł-ray burst7,8. The transient has physical parameters that broadly match the theoretical predictions of blue kilonovae from neutron-star mergers. The emitted electromagnetic radiation can be explained with an ejected mass of 0.04 ± 0.01 solar masses, with an opacity of less than 0.5 square centimetres per gram, at a velocity of 0.2 ± 0.1 times light speed. The power source is constrained to have a power-law slope of −1.2 ± 0.3, consistent with radioactive powering from r-process nuclides. (The r-process is a series of neutron capture reactions that synthesise many of the elements heavier than iron.) We identify line features in the spectra that are consistent with light r-process elements (atomic masses of 90–140). As it fades, the transient rapidly becomes red, and a higher-opacity, lanthanide-rich ejecta component may contribute to the emission. This indicates that neutron-star mergers produce gravitational waves and radioactively powered kilonovae, and are a nucleosynthetic source of the r-process element
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